Evaluation of Methods for Roots Processing on Removal of Anti-nutritional Factors of Selected Cultivars of Cassava (Manihot esculenta C.) Grown in Ethiopia

Locally grown cassava cultivars were subjected to study the effect of boiling, sun-drying and fermentation processing methods on removal of anti-nutritional factors. The root product flours were analyzed for anti-nutritional factors using standard methods. The data generated were statistically analyzed using statistical package for social scientists (SPSS). Out of the three processing techniques, fermentation of grated cassava roots for 72 hours sufficiently reduced HCN content to safe level (<10 ppm, WHO) of human consumption. The unprocessed cassava root of Gamo cultivar (48.00 ppm) belonged to the category of sweet or non-toxic. Whereas, cultivars of Hayik (78.07 ppm), 28 (83.70 ppm), 44/72-NW (129.20 ppm) and Koree (159.00 ppm) were found to be moderately toxic. Cultivars of 192 (211.17 ppm) and 5538-19 (247.20 ppm) belonged to highly bitter (highly toxic) cultivar too. Reduction in phytate and tannin levels were highest for sun-dried followed by fermented and boiled flours. However, reduction in oxalate contents were highest for fermented followed by boiled and sun-dried flours. The study reveals that the effect of processing methods found to be significant (P<0.05) on removing anti-nutritional factors

Changes in biochemical composition of Ethiopian Coffee arabica with growing region and traditional roasting

Updating the biochemical composition of coffee beans across the years is necessary. This is important to understand the vulnerability of coffee toward climate adaptation longitudinally. Accordingly, in this study the influence of growing area and traditional roasting on the biochemical composition of five common Ethiopian Arabica coffee beans collected in the harvest year of 2021/22 were investigated. With an average of 11.34 g/100 g, the Hararge and Jimma coffee beans had the highest crude fat content (p < 0.05). The crude protein content of the five varieties was in the range of 13–15 g/100 g, with respective highest and lowest contents in the (Hararge and Nekemte) and (Sidama and Yirgachefe) coffee beans (p < 0.05). The total phenolic content (TPC) of the coffee beans was in the order of Jimma (46.52) > Nekemte (44.55) > Sidama (44.31) > Hararge (39.02) > Yirgachefe (34.25) mg GAE/100 g. The 50% inhibitory concentration (IC50) of ascorbic acid, coffee bean extract from Jimma and Hararge against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical was 19.86, 20.22 and 20.02 μg/mL, respectively. The respective highest and lowest caffeine concentration was obtained in the Yirgachefe (10.38) and Hararge (7.55 g/100 g) coffee beans (p < 0.05). The Jimma, Sidama, and Nekemte coffee varieties had the highest chlorogenic acid content of 45 g/100 g (p > 0.05); whereas the lowest content was in Hararge coffee (36.78 g/100 g). While the caffeine concentration did not show significant (p > 0.05) difference, with all the coffee beans the roasting has reduced significantly the TPC, trigonelline and mainly the chlorogenic acid (p < 0.05). These data can update the existing facts on biochemical diversity of coffee beans in the country which can be used for evidence based innovations of climate adaptation in predicting the quality of coffee. Further recommendation of optimizing the traditional coffee processing method is supported from this study

Zirconium antimonate: Ion-exchange separation of some metal ions

Bull. Chem. Soc. Ethiop., 3(1), 47-50 (1989)

Zirconium selenite and thorium tellurite cation exchangers: Separation of some metal ions

Bull. Chem. Soc. Ethiop. 1994, 8(1) 1-8

Zirconium selenite and thorium tellurite cation exchangers: Separation of some metal ions

Bull. Chem. Soc. Ethiop. 1994, 8(1) 1-8

Zirconium antimonate: Ion-exchange separation of some metal ions

Bull. Chem. Soc. Ethiop., 3(1), 47-50 (1989)